VVR enables you to replicate data volumes in a shared disk group environment, for use with parallel applications that use Cluster Volume Manager (CVM) for high availability. You can replicate data volumes in a shared disk-group to a remote site, for disaster recovery or off-host processing.

A shared disk group is shared by all nodes in a cluster. A shared (or cluster-shareable) disk group is imported by all nodes in a cluster. Disks in a shared disk group must be physically accessible from all systems that join the cluster. VVR supports configurations in which both the Primary and Secondary disk group are shared, or either the Primary or the Secondary disk group is shared. Therefore, if the Primary disk group is shared, the Secondary disk group can be a private disk group or vice versa.

When replicating data from a shared disk group to the remote site, VVR works with the cluster functionality of Veritas Volume Manager. The cluster functionality of VxVM requires that one node act as the master node; all other nodes in the cluster are slave nodes.

For complete information on the cluster functionality (CVM) provided by VxVM, see the Veritas Storage Foundation Cluster File System High Availability Administrator's Guide

VVR includes the VCS agents for VVR to provide support for VVR in a shared disk group environment.

See Introducing the VCS agents for VVR.

For information about VCS, see the Veritas Cluster Server documentation set.

VVR adheres to the same model as CVM for most commands that change the configuration. However, some commands that are specific to VVR are exceptions and must be issued from the CVM master node. These commands include vradmin createpri, vxibc, vxrvg, and the vxrlink commands including vxrlink assoc, vxrlink dis, vxrlink att, vxrlink det, vxrlink pause, vxrlink resume, vxrlink restore, and vxrlink checkdelete. Informational commands such as vxrlink stats, vxrlink status, vxrlink verify, vxrlink cplist, and vxrlink updates can be run on any cluster node.

Note that the vxrlink status command and the vxrlink stats command display the same information on all the nodes in the cluster, whereas, the vxrvg stats command displays information pertaining to the node on which you run the command. The vxrvg stats command provides information about the reads and writes performed on the node on which you run it, therefore the information applies to that node only.